Methods: All patients who were diagnosed with a first episode of sigmoid diverticulitis will be evaluated for inclusion in the study, pending informed consent. Those patients who have evidence of complicated diverticulitis (fistula, abscess) will receive a recommendation to undergo elective sigmoid resection, while those who have a simple attack will be recruited in the cohort. Follow-up will be performed at yearly intervals through telephone interview with the patient. The duration of study is expected to last 10 years (2010-2020), with >50 new patients/year, for a total of >500 patients.